Whether Invisalign will work and how much time?

I had posted a question previously.my previous orthodontist hadn't told us that my teeth needs to be extracted to get perfect results and he attempted the treatment without extraction..fter tha treatment was over and when i couldn't see perfect results he says ull have to extract a front upper tooth so that space can be built up in my mouth...it was for 2 and half years i had already worn braces and now i want an alternative..can u suggest some really good doctor in mumbai, india for Invisalign?